Package index • shewhartr

Classical charts — variables

Classical Shewhart charts for measurements organised in rational subgroups (or as individuals).

shewhart_i_mr(): Individuals and Moving Range (I-MR) control chart
shewhart_xbar_r(): Xbar-R control chart for rational subgroups
shewhart_xbar_s(): Xbar-S control chart for rational subgroups

Classical charts — attributes

Charts for binary (defective/non-defective) and count (defects-per-unit) attributes.

shewhart_p(): p chart for the proportion of nonconforming items
shewhart_np(): np chart for the number of nonconforming items
shewhart_c(): c chart for the number of nonconformities
shewhart_u(): u chart for nonconformities per unit, variable inspection size

Regression-based chart

Control chart for trended processes, with optional automatic phase detection and a flexible model menu (linear, log, log-log, Gompertz, logistic, custom formula).

shewhart_regression(): Regression-based control chart for processes with trend

Memory-based charts

Charts that accumulate information across observations and so detect small persistent shifts faster than Shewhart-style charts.

shewhart_ewma(): Exponentially Weighted Moving Average (EWMA) control chart
shewhart_cusum(): Tabular CUSUM control chart

Multivariate charts

Charts for jointly monitoring several correlated quality characteristics; sensitive to shifts in the correlation structure that univariate charts can miss.

shewhart_hotelling(): Hotelling T-squared multivariate control chart
shewhart_mewma(): Multivariate EWMA control chart
shewhart_mcusum(): Multivariate CUSUM control chart (Crosier 1988)

Phase I / Phase II workflow

Explicit calibration and monitoring step, following the Phase I / Phase II framework articulated by Woodall (2000).

calibrate(): Phase I calibration of a control chart
monitor(): Phase II monitoring against pre-calibrated limits

Diagnostics & operating characteristics

Tools to evaluate and interpret a chart configuration: runs tests, ARL by simulation, residual diagnostic panels, Box-Cox guidance.

shewhart_runs(): Apply runs tests to a chart object or to raw vectors
shewhart_rules_available(): List available runs rules
shewhart_arl(): Estimate Average Run Length via Monte Carlo simulation
shewhart_diagnostics(): Tukey-style residual diagnostic panel
shewhart_box_cox(): Box-Cox profile log-likelihood

Process capability

shewhart_capability(): Process capability indices Cp, Cpk, Pp, Ppk

S3 methods (broom + ggplot2)

print(<shewhart_chart>): Print a Shewhart chart object
summary(<shewhart_chart>): Compact tibble-like summary
autoplot.shewhart_chart(): Plot a Shewhart chart with ggplot2
tidy(<shewhart_chart>): Tidy the control limits of a Shewhart chart
glance(<shewhart_chart>): Glance at a Shewhart chart's overall diagnostics
augment(<shewhart_chart>): Augment new data with control-chart annotations

Interactive plots

as_plotly(): Convert a Shewhart chart to an interactive plotly figure

Theme and palettes

Shared visual identity used by every autoplot() method. Pull these into your own ggplot layers when you want a chart that matches the rest of the package.

shewhart_theme(): Editorial-style ggplot2 theme used by every autoplot.shewhart_*
shewhart_palette(): Access the package's named colour palettes

Math helpers

Gompertz(): Gompertz growth function
SSgompertzDummy(): Self-starting Gompertz with an additive dummy term
fit_gompertz_dummy(): Convenience wrapper to fit SSgompertzDummy to a data frame
loglog(): Log-log transformation
iloglog(): Inverse log-log transformation
box_cox(): Apply / invert a Box-Cox power transformation
inv_box_cox(): Inverse Box-Cox transformation
shewhart_constants(): Look up Shewhart control chart constants
rolling_sum(): Rolling sum with a configurable window
color_hue(): Generate a qualitative HCL palette

Datasets

tablet_weight: Pharmaceutical tablet weights
bottle_fill: Bottle filling volumes
pcb_solder: Solder defects on printed circuit boards
claims_p: Daily insurance claim error rates
temperature_drift: Curing oven temperature drift
bacterial_growth: Bacterial growth curve (optical density)
cvd_recife: COVID-19 daily mortality, Recife, Brazil, 2020

Class predicates

is_shewhart_chart(): Shewhart chart S3 class